Hydraulic tools generally include a hydraulic ram or piston that can be extended to perform work such as crimping of workpieces or other functions. Ram extension is performed by pumping hydraulic fluid, under pressure, behind the ram thereby causing displacement of the ram. For hydraulic tools that include a manually operated pump such as a handle pump, performing a large number of repeated crimpings or other operations requires a corresponding large number of pumping operations by a user. This can become burdensome and significantly reduce the rate of operations performed by the user.
Hydraulic systems are known which provide rapid ram extension during no load conditions or prior to a ram position at which work is to be performed. A variety of strategies have been devised to increase the speed of ram extension. However, many if not all strategies involve complex hydraulic assemblies, and intricate hydraulic systems of valving and seals. As will be appreciated, such assemblies increase manufacturing costs and can be difficult to maintain. Accordingly, a need remains for new hydraulic systems, related methods, and tools using such hydraulic systems which are reliable and easy to maintain and which do not increase manufacturing costs.